title: Evaluation of an injectable silk fibroin enhanced calcium phosphate cement loaded with human recombinant bone morphogenetic protein-2 in ovine lumbar interbody fusion.
abstract: The objective of this study was to investigate the efficacy of an injectable calcium phosphate cement/silk fibroin/human recombinant bone morphogenetic protein-2 composite (CPC/SF/rhBMP-2) in an ovine interbody fusion model. Twenty-four mature sheep underwent anterior lumbar interbody fusion at the levels of L1/2, L3/4, and L5/6 with random implantation of CPC/SF, CPC/rhBMP-2, CPC/SF/rhBMP-2, or autogenous iliac bone. After the sheep were sacrificed, the fusion segments were evaluated by manual palpation, CT scan, undestructive biomechanical testing, undecalcified histology, and histomorphology. The fusion rates of CPC/SF/rhBMP-2 were 55.56% and 77.78% at 6 and 12 months, respectively. The fusion was superior to all the biomaterial grafts in stiffness, and reached the same stiffness as the autograft at 12 months. The new bone formation was less than autograft at 6 months, but similar with that at 12 months. However, the ceramic residue volume of CPC/SF/rhBMP-2 was significantly decreased compared with CPC/SF and CPC/rhBMP-2 at both times. The results indicated that CPC/SF/rhBMP-2 composite had excellent osteoconduction and osteoinduction, and balanced degradation and osteogenesis.
authors.affiliation: Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou 215006, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Gu
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.forename: Hui-Lin
authors.initials: HL
authors.lastname: Yang
authors.forename: Zong-Ping
authors.initials: ZP
authors.lastname: Luo
authors.forename: Tian-Si
authors.initials: TS
authors.lastname: Tang
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D012831:Bombyx / Q000378:metabolism; D001843:Bone Cements / Q000737:chemistry*; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D016025:Bone Transplantation; D002130:Calcium Phosphates / Q000737:chemistry*; D005349:Fibroins / Q000737:chemistry*; D006801:Humans; D008159:Lumbar Vertebrae / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry; D012756:Sheep; D047011:Silk / Q000737:chemistry*
chemical_list: C525718:BMP2 protein, human; D001843:Bone Cements; D055396:Bone Morphogenetic Protein 2; D018786:Bone Substitutes; D002130:Calcium Phosphates; D011994:Recombinant Proteins; D047011:Silk; D005349:Fibroins; C020243:calcium phosphate